Catch? Hmm... lemme see...
*unscrolls a rather large piece of parchment*
Alright, what do we have here... the green jello clause... from five weeks to a year... up to and including the letter 2...
Oh! Here we go!
The mystical nature of the limerick has been discussed by many, disputed by few, and ingested by none*. There are, of course, no clauses, pretenses, incongruencies, discombobulations, striations, or any other negative effect from said poetry**. Limericks are a joy and are created to please the individual reader, thus creating a positive atmosphere in any situation.
*None except for goats, shrews, badgers, sharks, sea cucumbers, and one little weasel found lost in Albania.
**All promises made are based on unreal facts. Please note that the limerick will likely cause the reader to turn into a fish of the poet's choice.
Uhh... so, you see? No catch! None whatsoever... <.<